Yes it will. If the wire is all the same then one fuse can protect from the switch to the battery BUT if you pull other loads off that buss bar then they need to be protected for the wires ampacity rating. If you lowered the ga of the wire from the buss bar to the switch from 1/0 to 1ga then you'd need a smaller fuse unless the fuse protecting the 1/0 was not to the max of the 1ga wires ampacity limit.

Yes really. The ABYC and Blue Sea make no exceptions or derating suggestions for short circuit protection for ANL fuses vs. other types. Now if you're using it for an inverter many manufacturers suggest using Class T because they blow slightly faster but that would not be a short circuit protection issue.

And you'll notice that Blue Seas own fuse sizing chart actually up-sizes on occasion to the next size fuse, which the ABYC recommends against:

You notice that the company you've referenced makes no changes in the ANL column for short circuit protection and the fuses rated value is what is used.

The face value rating of an ANL is perfectly acceptable to use with the ABYC ampacity chart for short circuit protection and Blue Sea makes it easy to understand in the above doc though I would down size rather than up size if pushing up against the 150% rule at least.

As I mentioned I have had this very conversation with John A. at ABYC, and Eric J., before he left, and they both made the point that the E-11 ampacity chart already takes all this into account.

Derating an ANL is certainly fine but there is no need for all that extra math if using it for short circuit protection and you can simply use the face value rating of the fuse...

Well, yes and no. Although we may be splitting hairs a bit here, please read the following statement from Blue Sea Systems regarding selection of their ANL fuses (bolding mine):

"Because ANL fuses behave differently than all other circuit protection devices, that is, their blow point value ranges from 140 to 266% of nominal value, the 80% rule doesn't work. It is necessary to use a different procedure to select a suitable ANL fuse. To choose a suitable ANL fuse, refer to the ANL Fuse Blow Point table above. According to the table, a 100A ANL fuse has a blow point of 175A. Therefore, a 100A ANL provides suitable protection for the 4 gauge AWG circuit in this example."

This is particularly relevant to the smaller ANL sizes, where the blowpoint -- after 8 minutes -- can be as much as 266% of the nominal rating.

Well, yes and no. Although we may be splitting hairs a bit here, please read the following statement from Blue Sea Systems regarding selection of their ANL fuses (bolding mine):

"Because ANL fuses behave differently than all other circuit protection devices, that is, their blow point value ranges from 140 to 266% of nominal value, the 80% rule doesn't work. It is necessary to use a different procedure to select a suitable ANL fuse. To choose a suitable ANL fuse, refer to the ANL Fuse Blow Point table above. According to the table, a 100A ANL fuse has a blow point of 175A. Therefore, a 100A ANL provides suitable protection for the 4 gauge AWG circuit in this example."

This is particularly relevant to the smaller ANL sizes, where the blowpoint -- after 8 minutes -- can be as much as 266% of the nominal rating.

Bill

I suspect that statement is not for short circuit protection which is what the ABYC E-11 ampacity table deals with.. Can you post a link to that?

What is the 80% rule they are referring to? When posted out of context with the rest of it sometimes it's hard to decipher that statement.

If you look at Blue Seas own short circuit protection suggestions they are not following their own advice, and that is why I suspect that statement is for device protection not short circuit..

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